Structural, persistent luminescence properties and trap characteristics of an orthosilicate phosphor: LiGaSiO4:Mn2+

A novel orthosilicate persistent phosphor LiGaSiO4:Mn2+ has been developed by solid state reaction method. The refined crystal structure of the LiGaSiO4 is solved. The photoluminescence and persistent spectra, decay curve and thermoluminescence have been investigated in details. It reveals that the Mn2+ at Li+ sites in the LiO4 tetrahedron are able to show intense green persistent luminescence, which can be measured for approximately 6 h and 2.1 h (0.32 mcd/m2) after exposure to ultraviolet and artificial sunlight irradiation. The trap distribution of phosphor is studied by using a series of excitation temperature dependent thermoluminescence experiments based on initial rising method. The different roles of the shallow and deep traps on the persistent luminescence have been revealed by the thermoluminescence fading experiments.